appendix

noun

ap·​pen·​dix ə-ˈpen-diks 

plural appendixes or appendices ə-ˈpen-də-ˌsēz 

1

a

: appendage

b

: supplementary material usually attached at the end of a piece of writing

The book's appendix includes a bibliography.

2

: a bodily outgrowth or process

specifically : vermiform appendix

Synonyms

• addendum
• afterword
• codicil
• excursus
• supplement

Examples of appendix in a Sentence

In your textbooks, turn to Appendix 3: Glossary of Terms.

The book has several appendixes.

Recent Examples on the Web

Parts of that appendix are currently being used by NSF staff to screen thousands of their active grants for compliance with President Trump's executive orders targeting diversity, equity and inclusion measures across the government. —Jonathan Lambert, NPR, 13 Feb. 2025

The memo included an appendix with names of the employees who would be fired. —Pat Milton, CBS News, 31 Jan. 2025

There is an appendix, first Appendix O now Appendix P that was added to the state’s building code that further elaborates the minimal standards that may not comply with the building code but are essentially good enough for basic health and safety. —Roger Valdez, Forbes, 7 Jan. 2025

Eventually, the group locates the fourth appendix and starts reading from it. —Erin Qualey, Vulture, 7 Feb. 2025

Word History

Etymology

Latin appendic-, appendix, from appendere — see append

First Known Use

1542, in the meaning defined at sense 1a

Phrases Containing appendix

• vermiform appendix

Kids Definition

appendix

noun

ap·​pen·​dix ə-ˈpen-diks 

plural appendixes or appendices -də-ˌsēz 

1

: additional material attached at the end of a piece of writing

2

: a small tube that is closed at one end and projects from the pouch marking the beginning of the large intestine in the lower right side of the abdomen

Medical Definition

appendix

noun

ap·​pen·​dix ə-ˈpen-diks 

plural appendixes or appendices -də-ˌsēz 

: a bodily outgrowth or process

specifically : vermiform appendix